40HL Measuring System
from GRAS

Microphones and Accelerometers

Typical applications and use

  • Measurements at very low sound pressurelevels
  • Measurements on hard-disk drives, computerproducts, anechoic rooms, quiet rooms, etc
  • Sound-power measurements at low levels


The 40HL comprises a special high-sensitive 1/2″ free-field measurement microphone and an integrated 1/2″ low-noise preamplifier. In combination, they connect to most high-quality input modules with LEMO 1B connector.


The preamplifier, a true 1/2″ low-noise amplifIer with LEMO 1B connector, has a built-in compensation filter for free-field microphones.


The 1/2″ microphone is an externally-polarized free field microphone with a specially reduced inherent noise floor in order to achieve a high dynamic range and wide frequency range. Its diaphragm is specially tuned to yield high sensitivity coupled with low internal noise.


Terms & Conditions

Download a copy of the AcSoft Equipment Rental Terms and Conditions here.

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